Provide a tagged allocation top pointer.

test/cctest/test-macro-assembler-x64.cc

Index: test/cctest/test-macro-assembler-x64.cc
diff --git a/test/cctest/test-macro-assembler-x64.cc b/test/cctest/test-macro-assembler-x64.cc
index 612f9e88a3d96e5808064a037707f1f0b88c3eb9..128c8a8871e17f712bc201843085e3b85e7f8ea3 100644
--- a/test/cctest/test-macro-assembler-x64.cc
+++ b/test/cctest/test-macro-assembler-x64.cc
@@ -33,6 +33,7 @@
 #include "src/factory.h"
 #include "src/macro-assembler.h"
 #include "test/cctest/cctest.h"
+#include "test/cctest/heap/heap-utils.h"
 
 namespace i = v8::internal;
 using i::Address;
@@ -91,6 +92,7 @@ using i::times_pointer_size;
 // with GCC.  A different convention is used on 64-bit windows.
 
 typedef int (*F0)();
+typedef intptr_t (*F1)();
 
 #define __ masm->
 
@@ -2728,5 +2730,197 @@ TEST(LoadAndStoreWithRepresentation) {
   CHECK_EQ(0, result);
 }
 
+// Helper for the tests below.
+template <typename Fun>
+void AssembleFunction(Isolate* isolate, size_t actual_size, byte* buffer,
+                      Fun f) {
+  MacroAssembler assembler(isolate, buffer, static_cast<int>(actual_size),
+                           v8::internal::CodeObjectRequired::kYes);
+  MacroAssembler* masm = &assembler;
+  Label exit;
+  EntryCode(masm);
+  f(masm);
+  ExitCode(masm);
+  __ ret(0);
+
+  CodeDesc desc;
+  masm->GetCode(&desc);
+}
+
+TEST(AllocateMacrosNoGCRequired) {
+  // Allocate an executable page of memory.
+  size_t actual_size;
+  byte* buffer = static_cast<byte*>(v8::base::OS::Allocate(
+      Assembler::kMinimalBufferSize, &actual_size, true));
+  CHECK(buffer);
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope handles(isolate);
+
+  AllocationFlags const kDoubleAligned =
+      static_cast<AllocationFlags>(DOUBLE_ALIGNMENT);
+  AllocationFlags const kNoAllocationFlags =
+      static_cast<AllocationFlags>(NO_ALLOCATION_FLAGS);
+
+#define CHECK_TAGGED(result) CHECK_EQ(result& i::kHeapObjectTag, 1);
+#define CHECK_DOUBLE_ALIGNED(result)                     \
+  do {                                                   \
+    CHECK_TAGGED((result));                              \
+    CHECK_EQ((result)&i::kDoubleAlignmentMaskTagged, 0); \
+  } while (false)
+
+  i::heap::GcAndSweep(isolate->heap(), i::AllocationSpace::NEW_SPACE);
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ Allocate(kPointerSize, rax, rcx, rdx, &gc_required,
+                  kNoAllocationFlags);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(i::kNoReason);
+      __ bind(&success);
+    });
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_TAGGED(test_result);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ Allocate(i::kDoubleSize, rax, rcx, rdx, &gc_required, kDoubleAligned);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(i::kNoReason);
+      __ bind(&success);
+    });
+    i::heap::MakeSureNewSpaceTopIsNotDoubleAligned(isolate->heap());
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_DOUBLE_ALIGNED(test_result);
+  }
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ movl(rbx, Immediate(kPointerSize));
+      __ Allocate(kPointerSize, rax, rcx, rdx, &gc_required,
+                  kNoAllocationFlags);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(i::kNoReason);
+      __ bind(&success);
+    });
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_TAGGED(test_result);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ movl(rbx, Immediate(i::kDoubleSize));
+      __ Allocate(rbx, rax, rcx, rdx, &gc_required, kDoubleAligned);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(i::kNoReason);
+      __ bind(&success);
+    });
+    i::heap::MakeSureNewSpaceTopIsNotDoubleAligned(isolate->heap());
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_DOUBLE_ALIGNED(test_result);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ movl(rbx, Immediate(2));
+      __ Allocate(0, i::times_4, rbx, rax, rcx, rdx, &gc_required,
+                  kNoAllocationFlags);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(i::kNoReason);
+      __ bind(&success);
+    });
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_TAGGED(test_result);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ movl(rbx, Immediate(i::kDoubleSize));
+      __ Allocate(i::FixedDoubleArray::kHeaderSize, i::times_8, rbx, rax, rcx,
+                  rdx, &gc_required, kDoubleAligned);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(i::kNoReason);
+      __ bind(&success);
+    });
+    i::heap::MakeSureNewSpaceTopIsNotDoubleAligned(isolate->heap());
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_DOUBLE_ALIGNED(test_result);
+  }
+#undef CHECK_TAGGED
+#undef CHECK_DOUBLE_ALIGNED
+}
+
+TEST(AllocateMacrosGCRequired) {
+  // Allocate an executable page of memory.
+  size_t actual_size;
+  byte* buffer = static_cast<byte*>(v8::base::OS::Allocate(
+      Assembler::kMinimalBufferSize, &actual_size, true));
+  CHECK(buffer);
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope handles(isolate);
+
+  AllocationFlags const kDoubleAligned =
+      static_cast<AllocationFlags>(DOUBLE_ALIGNMENT);
+
+  // Test that the macro jumps to the gc_required label if there's not enough
+  // space to allocate with double alignment.
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, end;
+      __ Allocate(kPointerSize, rax, rcx, rdx, &gc_required, kDoubleAligned);
+      __ xorl(rax, rax);
+      __ jmp(&end);
+      __ bind(&gc_required);
+      __ movl(rax, Immediate(1));
+      __ bind(&end);
+    });
+    i::heap::AllocateAllButNBytes(isolate->heap()->new_space(), 4);
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_EQ(test_result, 1);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, end;
+      __ movl(rbx, Immediate(kPointerSize));
+      __ Allocate(rbx, rax, rcx, rdx, &gc_required, kDoubleAligned);
+      __ xorl(rax, rax);
+      __ jmp(&end);
+      __ bind(&gc_required);
+      __ movl(rax, Immediate(1));
+      __ bind(&end);
+    });
+    i::heap::AllocateAllButNBytes(isolate->heap()->new_space(), 4);
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_EQ(test_result, 1);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, end;
+      __ movl(rbx, Immediate(kPointerSize));
+      __ Allocate(0, i::times_8, rbx, rax, rcx, rdx, &gc_required,
+                  kDoubleAligned);
+      __ xorl(rax, rax);
+      __ jmp(&end);
+      __ bind(&gc_required);
+      __ movl(rax, Immediate(1));
+      __ bind(&end);
+    });
+    i::heap::AllocateAllButNBytes(isolate->heap()->new_space(), 4);
+    intptr_t test_result = FUNCTION_CAST<F1>(buffer)();
+    CHECK_EQ(test_result, 1);
+  }
+}
 
 #undef __